With the development of the display technologies, TV sets, mobile phones, tablets, notebook computers, and other display devices have been increasingly widely applied in our daily life. At present, the display device can be generally categorized into liquid crystal display devices and light-emitting diode display devices.
A liquid crystal display device generally includes an array substrate, a color film substrate, and a liquid crystal layer arranged between the array substrate and the color filter substrate. The array substrate includes a base substrate, and an array of Thin Film Transistors (TFTs), and pixel electrodes, arranged on the base substrate, where the array of TFTs consists of gates, gate insulation layers, active layers, source and drain electrodes, etc. The color filter substrate includes a base substrate, and color filters, black matrixes, etc., arranged on the base substrate. When displaying on the display device, voltages of the pixel electrodes can be controlled respectively using the array of thin film transistors as switch elements, so that an image can be displayed by displaying at the different pixels in different colors and at different grayscales.